This invention relates generally to fluid flow within an inflatable device, and more particularly, to inflatable temperature control systems.
People spend several hours of each day sitting or lying down on a surface, including a bed (e.g., mattress, mattress pad, etc.) or a seat (e.g., office chair, sofa, seating pad, seating cushion, etc.) Since it is often desirable to manage and control the temperature of the surface that contacts the person (e.g., to remove the heat trapped in the contact area), several existing temperature control system solutions attempt to cool or heat the contact surface and/or the person to improve personal comfort.
For example, sofas and other pieces of furniture incorporate electrical and mechanical hardware inside the furniture and below the surface to be heated. Similarly, thermal blankets and mattress pads incorporate electrical heating elements to heat the contact surface. In addition to increasing the cost and complexity of the bed or seat, these systems also increase the risks of hazardous conditions such as fire and electric shock.
Other prior art solutions include the use of mattresses, pads, or blankets through which a conditioned fluid (e.g., air, gases, liquid) is blown or forced to cool or heat the contact surface, and in some cases, air is allowed to flow through openings in the contact surface. For those solutions wherein the conditioned fluid is not pressurized, prior art incorporates resilient and rigid elements (e.g., plastic or foam spacers, spines, tubes, etc.) to provide support for the weight of the person and/or to create passages for the fluid. These resilient and rigid elements increase the rigidness, size, and weight of these solutions, making the devices less portable as they cannot be stored or transported easily. A drawback for these embodiments is the requirement of a relatively thick comfort layer for the user to rest on. Because the comfort layer is a major barrier for providing efficient heat transfer during heating and/or cooling applications, the conditioned air is blown onto the users through a multiplicity of holes in the comfort layer. As a consequence, the conditioned air cannot be configured to flow in a closed loop, rendering these solutions inefficient due to the transfer of extra heat when the incoming air is at ambient temperature.
In some prior art solutions, an effort is made to replace the rigid elements with inflatable parts. For those solutions, the inflatable parts are designed to imitate the springs of a conventional mattress by directly replacing the steel springs found inside these mattresses. These inflatable parts acting as springs are presented in different shapes such as cylindrical, conical, square, etc., and they are installed in an array format extending throughout the inflatable mattress. The goal of these prior art embodiments is to allow the conditioned fluid to travel within the non-pressurized spaces formed between the inflatable parts or inflatable springs. However, the plurality of the inflatable springs does not guarantee an orderly flow of conditioned fluid and therefore the conditioned fluid may not reach the entire surface of the inflatable mattress creating considerable temperature differences on the top surface of the inflatable mattress. In addition, the required quantity of inflatable parts, acting as springs, adds to the complexity of the mattress construction.
Those solutions that continuously provide heating or cooling through a surface of an inflatable device require the pressurization of the conditioned fluid in order to provide support for the weight of a person. The pressurization of the conditioned fluid is normally done by using a compressor unit which compromises the energy efficiency of the heating and/or cooling system. So while these inflatable devices may themselves offer additional portability over prior art solutions (e.g., since the inflatable devices can be folded when not inflated to smaller sizes), the requirement of a large fan/compressor greatly diminishes this portability.
It would be advantageous to provide a temperature control system that overcomes the problems of these prior art solutions by providing a safer heating/cooling system with greater performance in terms of energy efficiency, flexibility, and portability.